Transcript Strategies for Reading the Ruler

Strategies for Reading the Ruler
Background – World Wide
 Two main systems of measurement
– Metric System
 Based on the number 10
– U.S. Customary System
 Based on halving or doubling units
Background – World Wide
 What countries besides the U.S. have not
adopted the metric system?
– All countries have adopted the metric system,
including the United States. However, in nearly
all countries people still use traditional units. For
a country to switch to metric is a process that
happens over time. Only 3 countries in the
world, have not officially adopted metric as their
primary system of measuring.
Background – World Wide
Myanmar
United States
(formly known
as Burma)
Liberia (Settled by
free-men and former
enslaved blacks after
America’s Civil war.
Three countries have not officially adopted the International System of Units
as their primary or sole system of measurement: Liberia, Myanmar, and the
United States.
Background – United States
 The U. S. has switched to Metric with
– Sporting Events - Olympics
– Military
– Medicine
– Scientific studies
Background – United States
 At this time, Manufacturing; Transportation; and
Construction Industries; are primarily using the U.S.
Customary system. In certain sectors, the conversion is
obvious (i.e. – Automobiles). However, in these industry
areas the changes have not been as complete.
 This is the reasoning for studying both measurement
systems used in the United States.
Background – United States
 Devices that you can measure with- such as a ruler…….
Metric Details
Millimeters and Centimeters
10 millimeters = 1 Centimeter
10 Centimeters = 1 Decimeter
1
2
2 centimeters
Lets find this point!
Metric Details
Millimeters and Centimeters
10 millimeters = 1 Centimeter
10 Centimeters = 1 Decimeter
1
2 78
36
4
5
Lets find this point!
8 millimeters
Metric Details
Millimeters and Centimeters
10 millimeters = 1 Centimeter
10 Centimeters = 1 Decimeter
10 Centimeters
or 1 Decimeter
1
Lets find this point!
U. S. Customary Details
Name – U.S. Customary System
12” in a Ruler
12” = 1 foot
 The units of the ruler are:
–
–
–
–
–
–
1/16” (smallest distance)
1/8”
¼”
½”
One Inch
One Foot (largest distance)
U. S. Customary Details
Inches (1”)
on a section of the ruler
1”
Counted the space which equals the inch unit.
2”
U. S. Customary Details
Half - Inches(1/2”)
½”
1”
on a section of the ruler
2”
1 of 2 parts in an inch
U. S. Customary Details
Fourth – (1/4”)
1/4”
on a section of the ruler
1”
2”
1 of 4 parts in an inch
U. S. Customary Details
Eighth – (1/8”)
1/8”
on a section of the ruler
1”
1 of 8 parts in an inch
2”
U. S. Customary Details
Sixteenths – (1/16”)
1/16”
on a section of the ruler
1”
1 of 16 parts in an inch
2”
Strategies for reading the ruler
 TWO WAYS OF LEARNING
– Traditional & Patterns
– Traditional
 Fractions and reducing
 Example – Count every line to that point then divide by an even number on the
top and bottom if it needs reduced
Count to the whole number for the bottom of the fraction
1 2 3 4 5 6 7 8 9 10 11 121314 15 16
6
16
.
.
2
3
=
2
8
1”
Lets find this point!
2”
Strategies for reading the ruler
 TWO WAYS OF LEARNING
– Traditional
 Fractions and reducing
 Example – Count the lines then divide by an even number on the top and
bottom if it needs reduced.
Count to the whole number for the bottom of the fraction
1 2 3 4 5 6 7 8 9 10 11 12131415 16
4
16
.
.
4
1
=
4
4
1”
Lets find this point!
2”
Strategies for reading the ruler
 SECOND WAY OF LEARNING
– Non -Traditional
 Patterns –
 Example – Count only lines that are the length or longer than the destination line.
Count to the whole number for the bottom of the fraction
1 2
3
8
Same
length
3
4
5
7
8
Longer
length
Three of 8
parts of an
inch!
No reducing
needed!
6
1”
Lets find this point!
2”
Strategies for reading the ruler
 SECOND WAY OF LEARNING
– Non -Traditional
 Patterns –
 Example – Counting patterns will always be in lowest terms. No reducing needed!
Count to the whole number for the bottom of the fraction
1
2
3
4
1
4
One of 4
parts of
an inch!
1”
Lets find this point!
2”
Strategies for reading the ruler
 Count whole numbers first!
– Past an inch
 Count whole numbers then the fraction in either method.
 Example Count to the whole number for the bottom of the fraction
1
1 1”
4
2
3
4
One whole Inch
1”
2”
Lets find this point!
Summary
 TWO Measurement Systems
Metric
Each line is a millimeter and every 10 lines is a centimeter.
Get Ready to Practice and Good luck!
U.S. Customary
Halving or doubling units.
Units – 1/16, 1/8, ¼ , ½ or inch
Can count each line & reduce or count patterns.